1. Field of the Invention
The invention disclosed relates wear detection in electrical contacts.
2. Discussion of the Related Art
The switching of electrical currents produces arcing between switch contacts, having the potential to cause considerable damage to the contacts. Metal atoms are eroded and ionized from the contact, resulting in arc erosion. Arc erosion on the contacts of a switch impair good contact joint integrity when the switch is fully closed.
Contact wear detection is needed to indicate whether switch contacts need replacement. Often, the contacts are either replaced too early or too late in the life cycle, merely on an external schedule or after a set number of operations. Earlier attempts to detect contact wear focused a source of ultraviolet light on a fluorescent trace material previously applied to an electrical contact. The amount of optical fluorescence detected from the UV-illuminated trace material, was related to the amount of wear of the contacts.